blender
/
blender
136
406
Fork 590
Code Issues 6.2k Pull Requests 764 Projects 19 Wiki Activity

Fix T83391: Knife sometimes snaps to object center 

Knife snapping logic assumed having a face under the cursor meant
the projected positions were set.

This is not always the case as failure to ray-cast uses the back-buffer
as a fallback.
This commit is contained in:
Campbell Barton 2021-03-29 13:14:23 +11:00
parent e47f5cf197
commit 27a7b2e27a
Notes: blender-bot 2023-02-14 09:24:53 +01:00 
Referenced by issue #83391, Knife tool renders future points incorrectly once again
1 changed files with 30 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
source/blender/editors/mesh/editmesh_knife.c
View File

@ -146,6 +146,8 @@ typedef struct KnifePosData {
KnifeVert *vert;
KnifeEdge *edge;
BMFace *bmface;
/** When true, the cursor isn't over a face. */
bool is_space;
float mval[2]; /* mouse screen position (may be non-integral if snapped to something) */
@ -2218,7 +2220,15 @@ static bool knife_snap_angle(KnifeTool_OpData *kcd)
return true;
}
static void knife_snap_update_from_mval(KnifeTool_OpData *kcd, const float mval[2])
/**
* \return true when `kcd->curr.co` & `kcd->curr.cage` are set.
*
* In this case `is_space` is nearly always false.
* There are some situations when vertex or edge can be snapped to, when `is_space` is true.
* In this case the selection-buffer is used to select the face,
* then the closest `vert` or `edge` is set, and those will enable `is_co_set`.
*/
static bool knife_snap_update_from_mval(KnifeTool_OpData *kcd, const float mval[2])
{
knife_pos_data_clear(&kcd->curr);
copy_v2_v2(kcd->curr.mval, mval);
@ -2236,29 +2246,39 @@ static void knife_snap_update_from_mval(KnifeTool_OpData *kcd, const float mval[
kcd->curr.bmface = knife_find_closest_face(
kcd, kcd->curr.co, kcd->curr.cage, &kcd->curr.is_space);
bool is_co_set = false;
if (kcd->curr.bmface) {
if (kcd->curr.is_space == false) {
is_co_set = true;
}
kcd->curr.vert = knife_find_closest_vert_of_face(
kcd, kcd->curr.bmface, kcd->curr.co, kcd->curr.cage);
if (!kcd->curr.vert &&
/* no edge snapping while dragging (edges are too sticky when cuts are immediate) */
!kcd->is_drag_hold) {
kcd->curr.edge = knife_find_closest_edge_of_face(
kcd, kcd->curr.bmface, kcd->curr.co, kcd->curr.cage);
if (kcd->curr.vert) {
is_co_set = true;
}
else {
/* No edge snapping while dragging (edges are too sticky when cuts are immediate). */
if (!kcd->is_drag_hold) {
kcd->curr.edge = knife_find_closest_edge_of_face(
kcd, kcd->curr.bmface, kcd->curr.co, kcd->curr.cage);
if (kcd->curr.edge) {
is_co_set = true;
}
}
}
}
return is_co_set;
}
/* update active knife edge/vert pointers */
static int knife_update_active(KnifeTool_OpData *kcd)
{
knife_snap_update_from_mval(kcd, kcd->mval);
/* if no hits are found this would normally default to (0, 0, 0) so instead
* get a point at the mouse ray closest to the previous point.
* Note that drawing lines in `free-space` isn't properly supported
* but there's no guarantee (0, 0, 0) has any geometry either - campbell */
if (kcd->curr.vert == NULL && kcd->curr.edge == NULL && kcd->curr.bmface == NULL) {
if (!knife_snap_update_from_mval(kcd, kcd->mval)) {
float origin[3];
float origin_ofs[3];